Abstract: | The first isolation and identification of the infectious pancreatic necrosis virus in trout in Czechoslovakia is described. The RTG-2, PG and CHSE cell lines were used for isolation and the identification was made by the methods of electron microscopy, cross virus-neutralizing test, and immunofluorescence. As demonstrated, all the isolates in the Czechoslovak territory are serologically identical and are closely related (or perhaps congruent) with the Sp reference strain which has the highest frequency in Europe. The described methodical procedure is also applicable to the diagnostics of other virus diseases of fish. |